<div class="wrapper" id="search-box">
    <form action="<?=site_url('thangthanh/search/')?>" method="post">
	    <input type="text" value="Tìm kiếm..." name="txtTuKhoa" onclick="this.value=''" id="search-field"><input type="submit" id="search-btn" name="btnSearch" value="">
    </form>
</div>